1. Field
One or more aspects of embodiments of the present invention relate to a grid-connected power storage system for connecting a power generation system to a grid to supply power to a load system and a method for controlling the grid-connected power storage system, and more particularly, to a grid-connected power storage system with increased capacity and a method for controlling the grid-connected power storage system.
2. Description of Related Art
The importance of new-renewable power has been recognized as changes occur in domestic and overseas environments. New-renewable power has been recognized as a solution to both an exhaustion problem of fossil fuel and an environmental problem of using the fossil fuel to produce power.
In particular, a photovoltaic generation system for generating power by using solar power does not generate pollutant, and is easily installed and maintained. Thus, the photovoltaic generation system has been spotlighted. Such a photovoltaic generation system can be classified as either an independent generation system which operates independently, or a grid-connected generation system which operates in connection with a commercial power grid. Internal circuit elements of a converter and an inverter constituting a photovoltaic generation system are determined according to a rated voltage or a rated current which has been set when the photovoltaic generation system is designed. Since a capacity of a photovoltaic generation system is fixed in this case, an additional system is to be installed when the capacity of the photovoltaic generation system is increased. Therefore, it is difficult to ensure a space and power of the photovoltaic generation system.